/* ehopt.c--optimize gcc exception frame information.
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/* ehopt.c--optimize gcc exception frame information.
|
Copyright 1998, 2000, 2001, 2003, 2005, 2007 Free Software Foundation, Inc.
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Copyright 1998, 2000, 2001, 2003, 2005, 2007 Free Software Foundation, Inc.
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Written by Ian Lance Taylor <ian@cygnus.com>.
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Written by Ian Lance Taylor <ian@cygnus.com>.
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This file is part of GAS, the GNU Assembler.
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This file is part of GAS, the GNU Assembler.
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GAS is free software; you can redistribute it and/or modify
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GAS is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3, or (at your option)
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the Free Software Foundation; either version 3, or (at your option)
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any later version.
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any later version.
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|
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GAS is distributed in the hope that it will be useful,
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GAS is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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GNU General Public License for more details.
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|
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You should have received a copy of the GNU General Public License
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You should have received a copy of the GNU General Public License
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along with GAS; see the file COPYING. If not, write to the Free
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along with GAS; see the file COPYING. If not, write to the Free
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Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
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Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
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02110-1301, USA. */
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02110-1301, USA. */
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#include "as.h"
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#include "as.h"
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#include "subsegs.h"
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#include "subsegs.h"
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/* We include this ELF file, even though we may not be assembling for
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/* We include this ELF file, even though we may not be assembling for
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ELF, since the exception frame information is always in a format
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ELF, since the exception frame information is always in a format
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derived from DWARF. */
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derived from DWARF. */
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#include "elf/dwarf2.h"
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#include "elf/dwarf2.h"
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/* Try to optimize gcc 2.8 exception frame information.
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/* Try to optimize gcc 2.8 exception frame information.
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|
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Exception frame information is emitted for every function in the
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Exception frame information is emitted for every function in the
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.eh_frame or .debug_frame sections. Simple information for a function
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.eh_frame or .debug_frame sections. Simple information for a function
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with no exceptions looks like this:
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with no exceptions looks like this:
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__FRAME_BEGIN__:
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__FRAME_BEGIN__:
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.4byte .LLCIE1 / Length of Common Information Entry
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.4byte .LLCIE1 / Length of Common Information Entry
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.LSCIE1:
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.LSCIE1:
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#if .eh_frame
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#if .eh_frame
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.4byte 0x0 / CIE Identifier Tag
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.4byte 0x0 / CIE Identifier Tag
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#elif .debug_frame
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#elif .debug_frame
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.4byte 0xffffffff / CIE Identifier Tag
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.4byte 0xffffffff / CIE Identifier Tag
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#endif
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#endif
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.byte 0x1 / CIE Version
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.byte 0x1 / CIE Version
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.byte 0x0 / CIE Augmentation (none)
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.byte 0x0 / CIE Augmentation (none)
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.byte 0x1 / ULEB128 0x1 (CIE Code Alignment Factor)
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.byte 0x1 / ULEB128 0x1 (CIE Code Alignment Factor)
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.byte 0x7c / SLEB128 -4 (CIE Data Alignment Factor)
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.byte 0x7c / SLEB128 -4 (CIE Data Alignment Factor)
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.byte 0x8 / CIE RA Column
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.byte 0x8 / CIE RA Column
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.byte 0xc / DW_CFA_def_cfa
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.byte 0xc / DW_CFA_def_cfa
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.byte 0x4 / ULEB128 0x4
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.byte 0x4 / ULEB128 0x4
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.byte 0x4 / ULEB128 0x4
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.byte 0x4 / ULEB128 0x4
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.byte 0x88 / DW_CFA_offset, column 0x8
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.byte 0x88 / DW_CFA_offset, column 0x8
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.byte 0x1 / ULEB128 0x1
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.byte 0x1 / ULEB128 0x1
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.align 4
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.align 4
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.LECIE1:
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.LECIE1:
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.set .LLCIE1,.LECIE1-.LSCIE1 / CIE Length Symbol
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.set .LLCIE1,.LECIE1-.LSCIE1 / CIE Length Symbol
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.4byte .LLFDE1 / FDE Length
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.4byte .LLFDE1 / FDE Length
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.LSFDE1:
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.LSFDE1:
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.4byte .LSFDE1-__FRAME_BEGIN__ / FDE CIE offset
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.4byte .LSFDE1-__FRAME_BEGIN__ / FDE CIE offset
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.4byte .LFB1 / FDE initial location
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.4byte .LFB1 / FDE initial location
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.4byte .LFE1-.LFB1 / FDE address range
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.4byte .LFE1-.LFB1 / FDE address range
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.byte 0x4 / DW_CFA_advance_loc4
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.byte 0x4 / DW_CFA_advance_loc4
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.4byte .LCFI0-.LFB1
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.4byte .LCFI0-.LFB1
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.byte 0xe / DW_CFA_def_cfa_offset
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.byte 0xe / DW_CFA_def_cfa_offset
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.byte 0x8 / ULEB128 0x8
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.byte 0x8 / ULEB128 0x8
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.byte 0x85 / DW_CFA_offset, column 0x5
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.byte 0x85 / DW_CFA_offset, column 0x5
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.byte 0x2 / ULEB128 0x2
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.byte 0x2 / ULEB128 0x2
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.byte 0x4 / DW_CFA_advance_loc4
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.byte 0x4 / DW_CFA_advance_loc4
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.4byte .LCFI1-.LCFI0
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.4byte .LCFI1-.LCFI0
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.byte 0xd / DW_CFA_def_cfa_register
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.byte 0xd / DW_CFA_def_cfa_register
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.byte 0x5 / ULEB128 0x5
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.byte 0x5 / ULEB128 0x5
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.byte 0x4 / DW_CFA_advance_loc4
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.byte 0x4 / DW_CFA_advance_loc4
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.4byte .LCFI2-.LCFI1
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.4byte .LCFI2-.LCFI1
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.byte 0x2e / DW_CFA_GNU_args_size
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.byte 0x2e / DW_CFA_GNU_args_size
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.byte 0x4 / ULEB128 0x4
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.byte 0x4 / ULEB128 0x4
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.byte 0x4 / DW_CFA_advance_loc4
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.byte 0x4 / DW_CFA_advance_loc4
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.4byte .LCFI3-.LCFI2
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.4byte .LCFI3-.LCFI2
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.byte 0x2e / DW_CFA_GNU_args_size
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.byte 0x2e / DW_CFA_GNU_args_size
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.byte 0x0 / ULEB128 0x0
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.byte 0x0 / ULEB128 0x0
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.align 4
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.align 4
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.LEFDE1:
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.LEFDE1:
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.set .LLFDE1,.LEFDE1-.LSFDE1 / FDE Length Symbol
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.set .LLFDE1,.LEFDE1-.LSFDE1 / FDE Length Symbol
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|
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The immediate issue we can address in the assembler is the
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The immediate issue we can address in the assembler is the
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DW_CFA_advance_loc4 followed by a four byte value. The value is
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DW_CFA_advance_loc4 followed by a four byte value. The value is
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the difference of two addresses in the function. Since gcc does
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the difference of two addresses in the function. Since gcc does
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not know this value, it always uses four bytes. We will know the
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not know this value, it always uses four bytes. We will know the
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value at the end of assembly, so we can do better. */
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value at the end of assembly, so we can do better. */
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struct cie_info
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struct cie_info
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{
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{
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unsigned code_alignment;
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unsigned code_alignment;
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int z_augmentation;
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int z_augmentation;
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};
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};
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static int get_cie_info (struct cie_info *);
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static int get_cie_info (struct cie_info *);
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/* Extract information from the CIE. */
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/* Extract information from the CIE. */
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static int
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static int
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get_cie_info (struct cie_info *info)
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get_cie_info (struct cie_info *info)
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{
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{
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fragS *f;
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fragS *f;
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fixS *fix;
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fixS *fix;
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int offset;
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int offset;
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char CIE_id;
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char CIE_id;
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char augmentation[10];
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char augmentation[10];
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int iaug;
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int iaug;
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int code_alignment = 0;
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int code_alignment = 0;
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/* We should find the CIE at the start of the section. */
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/* We should find the CIE at the start of the section. */
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f = seg_info (now_seg)->frchainP->frch_root;
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f = seg_info (now_seg)->frchainP->frch_root;
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fix = seg_info (now_seg)->frchainP->fix_root;
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fix = seg_info (now_seg)->frchainP->fix_root;
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/* Look through the frags of the section to find the code alignment. */
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/* Look through the frags of the section to find the code alignment. */
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/* First make sure that the CIE Identifier Tag is 0/-1. */
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/* First make sure that the CIE Identifier Tag is 0/-1. */
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if (strcmp (segment_name (now_seg), ".debug_frame") == 0)
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if (strcmp (segment_name (now_seg), ".debug_frame") == 0)
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CIE_id = (char)0xff;
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CIE_id = (char)0xff;
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else
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else
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CIE_id = 0;
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CIE_id = 0;
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offset = 4;
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offset = 4;
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while (f != NULL && offset >= f->fr_fix)
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while (f != NULL && offset >= f->fr_fix)
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{
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{
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offset -= f->fr_fix;
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offset -= f->fr_fix;
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f = f->fr_next;
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f = f->fr_next;
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}
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}
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if (f == NULL
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if (f == NULL
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|| f->fr_fix - offset < 4
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|| f->fr_fix - offset < 4
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|| f->fr_literal[offset] != CIE_id
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|| f->fr_literal[offset] != CIE_id
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|| f->fr_literal[offset + 1] != CIE_id
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|| f->fr_literal[offset + 1] != CIE_id
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|| f->fr_literal[offset + 2] != CIE_id
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|| f->fr_literal[offset + 2] != CIE_id
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|| f->fr_literal[offset + 3] != CIE_id)
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|| f->fr_literal[offset + 3] != CIE_id)
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return 0;
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return 0;
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/* Next make sure the CIE version number is 1. */
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/* Next make sure the CIE version number is 1. */
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offset += 4;
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offset += 4;
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while (f != NULL && offset >= f->fr_fix)
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while (f != NULL && offset >= f->fr_fix)
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{
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{
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offset -= f->fr_fix;
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offset -= f->fr_fix;
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f = f->fr_next;
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f = f->fr_next;
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}
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}
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if (f == NULL
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if (f == NULL
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|| f->fr_fix - offset < 1
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|| f->fr_fix - offset < 1
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|| f->fr_literal[offset] != 1)
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|| f->fr_literal[offset] != 1)
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return 0;
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return 0;
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/* Skip the augmentation (a null terminated string). */
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/* Skip the augmentation (a null terminated string). */
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iaug = 0;
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iaug = 0;
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++offset;
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++offset;
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while (1)
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while (1)
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{
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{
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while (f != NULL && offset >= f->fr_fix)
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while (f != NULL && offset >= f->fr_fix)
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{
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{
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offset -= f->fr_fix;
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offset -= f->fr_fix;
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f = f->fr_next;
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f = f->fr_next;
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}
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}
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if (f == NULL)
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if (f == NULL)
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return 0;
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return 0;
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while (offset < f->fr_fix && f->fr_literal[offset] != '\0')
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while (offset < f->fr_fix && f->fr_literal[offset] != '\0')
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{
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{
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if ((size_t) iaug < (sizeof augmentation) - 1)
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if ((size_t) iaug < (sizeof augmentation) - 1)
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{
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{
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augmentation[iaug] = f->fr_literal[offset];
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augmentation[iaug] = f->fr_literal[offset];
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++iaug;
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++iaug;
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}
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}
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++offset;
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++offset;
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}
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}
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if (offset < f->fr_fix)
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if (offset < f->fr_fix)
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break;
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break;
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}
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}
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++offset;
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++offset;
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while (f != NULL && offset >= f->fr_fix)
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while (f != NULL && offset >= f->fr_fix)
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{
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{
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offset -= f->fr_fix;
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offset -= f->fr_fix;
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f = f->fr_next;
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f = f->fr_next;
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}
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}
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if (f == NULL)
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if (f == NULL)
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return 0;
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return 0;
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augmentation[iaug] = '\0';
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augmentation[iaug] = '\0';
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if (augmentation[0] == '\0')
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if (augmentation[0] == '\0')
|
{
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{
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/* No augmentation. */
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/* No augmentation. */
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}
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}
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else if (strcmp (augmentation, "eh") == 0)
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else if (strcmp (augmentation, "eh") == 0)
|
{
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{
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/* We have to skip a pointer. Unfortunately, we don't know how
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/* We have to skip a pointer. Unfortunately, we don't know how
|
large it is. We find out by looking for a matching fixup. */
|
large it is. We find out by looking for a matching fixup. */
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while (fix != NULL
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while (fix != NULL
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&& (fix->fx_frag != f || fix->fx_where != offset))
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&& (fix->fx_frag != f || fix->fx_where != offset))
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fix = fix->fx_next;
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fix = fix->fx_next;
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if (fix == NULL)
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if (fix == NULL)
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offset += 4;
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offset += 4;
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else
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else
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offset += fix->fx_size;
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offset += fix->fx_size;
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while (f != NULL && offset >= f->fr_fix)
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while (f != NULL && offset >= f->fr_fix)
|
{
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{
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offset -= f->fr_fix;
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offset -= f->fr_fix;
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f = f->fr_next;
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f = f->fr_next;
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}
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}
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if (f == NULL)
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if (f == NULL)
|
return 0;
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return 0;
|
}
|
}
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else if (augmentation[0] != 'z')
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else if (augmentation[0] != 'z')
|
return 0;
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return 0;
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|
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/* We're now at the code alignment factor, which is a ULEB128. If
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/* We're now at the code alignment factor, which is a ULEB128. If
|
it isn't a single byte, forget it. */
|
it isn't a single byte, forget it. */
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|
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code_alignment = f->fr_literal[offset] & 0xff;
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code_alignment = f->fr_literal[offset] & 0xff;
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if ((code_alignment & 0x80) != 0)
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if ((code_alignment & 0x80) != 0)
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code_alignment = 0;
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code_alignment = 0;
|
|
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info->code_alignment = code_alignment;
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info->code_alignment = code_alignment;
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info->z_augmentation = (augmentation[0] == 'z');
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info->z_augmentation = (augmentation[0] == 'z');
|
|
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return 1;
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return 1;
|
}
|
}
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|
|
/* This function is called from emit_expr. It looks for cases which
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/* This function is called from emit_expr. It looks for cases which
|
we can optimize.
|
we can optimize.
|
|
|
Rather than try to parse all this information as we read it, we
|
Rather than try to parse all this information as we read it, we
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look for a single byte DW_CFA_advance_loc4 followed by a 4 byte
|
look for a single byte DW_CFA_advance_loc4 followed by a 4 byte
|
difference. We turn that into a rs_cfa_advance frag, and handle
|
difference. We turn that into a rs_cfa_advance frag, and handle
|
those frags at the end of the assembly. If the gcc output changes
|
those frags at the end of the assembly. If the gcc output changes
|
somewhat, this optimization may stop working.
|
somewhat, this optimization may stop working.
|
|
|
This function returns non-zero if it handled the expression and
|
This function returns non-zero if it handled the expression and
|
emit_expr should not do anything, or zero otherwise. It can also
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emit_expr should not do anything, or zero otherwise. It can also
|
change *EXP and *PNBYTES. */
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change *EXP and *PNBYTES. */
|
|
|
int
|
int
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check_eh_frame (expressionS *exp, unsigned int *pnbytes)
|
check_eh_frame (expressionS *exp, unsigned int *pnbytes)
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{
|
{
|
struct frame_data
|
struct frame_data
|
{
|
{
|
enum frame_state
|
enum frame_state
|
{
|
{
|
state_idle,
|
state_idle,
|
state_saw_size,
|
state_saw_size,
|
state_saw_cie_offset,
|
state_saw_cie_offset,
|
state_saw_pc_begin,
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state_saw_pc_begin,
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state_seeing_aug_size,
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state_seeing_aug_size,
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state_skipping_aug,
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state_skipping_aug,
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state_wait_loc4,
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state_wait_loc4,
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state_saw_loc4,
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state_saw_loc4,
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state_error,
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state_error,
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} state;
|
} state;
|
|
|
int cie_info_ok;
|
int cie_info_ok;
|
struct cie_info cie_info;
|
struct cie_info cie_info;
|
|
|
symbolS *size_end_sym;
|
symbolS *size_end_sym;
|
fragS *loc4_frag;
|
fragS *loc4_frag;
|
int loc4_fix;
|
int loc4_fix;
|
|
|
int aug_size;
|
int aug_size;
|
int aug_shift;
|
int aug_shift;
|
};
|
};
|
|
|
static struct frame_data eh_frame_data;
|
static struct frame_data eh_frame_data;
|
static struct frame_data debug_frame_data;
|
static struct frame_data debug_frame_data;
|
struct frame_data *d;
|
struct frame_data *d;
|
|
|
/* Don't optimize. */
|
/* Don't optimize. */
|
if (flag_traditional_format)
|
if (flag_traditional_format)
|
return 0;
|
return 0;
|
|
|
#ifdef md_allow_eh_opt
|
#ifdef md_allow_eh_opt
|
if (! md_allow_eh_opt)
|
if (! md_allow_eh_opt)
|
return 0;
|
return 0;
|
#endif
|
#endif
|
|
|
/* Select the proper section data. */
|
/* Select the proper section data. */
|
if (strcmp (segment_name (now_seg), ".eh_frame") == 0)
|
if (strcmp (segment_name (now_seg), ".eh_frame") == 0)
|
d = &eh_frame_data;
|
d = &eh_frame_data;
|
else if (strcmp (segment_name (now_seg), ".debug_frame") == 0)
|
else if (strcmp (segment_name (now_seg), ".debug_frame") == 0)
|
d = &debug_frame_data;
|
d = &debug_frame_data;
|
else
|
else
|
return 0;
|
return 0;
|
|
|
if (d->state >= state_saw_size && S_IS_DEFINED (d->size_end_sym))
|
if (d->state >= state_saw_size && S_IS_DEFINED (d->size_end_sym))
|
{
|
{
|
/* We have come to the end of the CIE or FDE. See below where
|
/* We have come to the end of the CIE or FDE. See below where
|
we set saw_size. We must check this first because we may now
|
we set saw_size. We must check this first because we may now
|
be looking at the next size. */
|
be looking at the next size. */
|
d->state = state_idle;
|
d->state = state_idle;
|
}
|
}
|
|
|
switch (d->state)
|
switch (d->state)
|
{
|
{
|
case state_idle:
|
case state_idle:
|
if (*pnbytes == 4)
|
if (*pnbytes == 4)
|
{
|
{
|
/* This might be the size of the CIE or FDE. We want to know
|
/* This might be the size of the CIE or FDE. We want to know
|
the size so that we don't accidentally optimize across an FDE
|
the size so that we don't accidentally optimize across an FDE
|
boundary. We recognize the size in one of two forms: a
|
boundary. We recognize the size in one of two forms: a
|
symbol which will later be defined as a difference, or a
|
symbol which will later be defined as a difference, or a
|
subtraction of two symbols. Either way, we can tell when we
|
subtraction of two symbols. Either way, we can tell when we
|
are at the end of the FDE because the symbol becomes defined
|
are at the end of the FDE because the symbol becomes defined
|
(in the case of a subtraction, the end symbol, from which the
|
(in the case of a subtraction, the end symbol, from which the
|
start symbol is being subtracted). Other ways of describing
|
start symbol is being subtracted). Other ways of describing
|
the size will not be optimized. */
|
the size will not be optimized. */
|
if ((exp->X_op == O_symbol || exp->X_op == O_subtract)
|
if ((exp->X_op == O_symbol || exp->X_op == O_subtract)
|
&& ! S_IS_DEFINED (exp->X_add_symbol))
|
&& ! S_IS_DEFINED (exp->X_add_symbol))
|
{
|
{
|
d->state = state_saw_size;
|
d->state = state_saw_size;
|
d->size_end_sym = exp->X_add_symbol;
|
d->size_end_sym = exp->X_add_symbol;
|
}
|
}
|
}
|
}
|
break;
|
break;
|
|
|
case state_saw_size:
|
case state_saw_size:
|
case state_saw_cie_offset:
|
case state_saw_cie_offset:
|
/* Assume whatever form it appears in, it appears atomically. */
|
/* Assume whatever form it appears in, it appears atomically. */
|
d->state += 1;
|
d->state += 1;
|
break;
|
break;
|
|
|
case state_saw_pc_begin:
|
case state_saw_pc_begin:
|
/* Decide whether we should see an augmentation. */
|
/* Decide whether we should see an augmentation. */
|
if (! d->cie_info_ok
|
if (! d->cie_info_ok
|
&& ! (d->cie_info_ok = get_cie_info (&d->cie_info)))
|
&& ! (d->cie_info_ok = get_cie_info (&d->cie_info)))
|
d->state = state_error;
|
d->state = state_error;
|
else if (d->cie_info.z_augmentation)
|
else if (d->cie_info.z_augmentation)
|
{
|
{
|
d->state = state_seeing_aug_size;
|
d->state = state_seeing_aug_size;
|
d->aug_size = 0;
|
d->aug_size = 0;
|
d->aug_shift = 0;
|
d->aug_shift = 0;
|
}
|
}
|
else
|
else
|
d->state = state_wait_loc4;
|
d->state = state_wait_loc4;
|
break;
|
break;
|
|
|
case state_seeing_aug_size:
|
case state_seeing_aug_size:
|
/* Bytes == -1 means this comes from an leb128 directive. */
|
/* Bytes == -1 means this comes from an leb128 directive. */
|
if ((int)*pnbytes == -1 && exp->X_op == O_constant)
|
if ((int)*pnbytes == -1 && exp->X_op == O_constant)
|
{
|
{
|
d->aug_size = exp->X_add_number;
|
d->aug_size = exp->X_add_number;
|
d->state = state_skipping_aug;
|
d->state = state_skipping_aug;
|
}
|
}
|
else if (*pnbytes == 1 && exp->X_op == O_constant)
|
else if (*pnbytes == 1 && exp->X_op == O_constant)
|
{
|
{
|
unsigned char byte = exp->X_add_number;
|
unsigned char byte = exp->X_add_number;
|
d->aug_size |= (byte & 0x7f) << d->aug_shift;
|
d->aug_size |= (byte & 0x7f) << d->aug_shift;
|
d->aug_shift += 7;
|
d->aug_shift += 7;
|
if ((byte & 0x80) == 0)
|
if ((byte & 0x80) == 0)
|
d->state = state_skipping_aug;
|
d->state = state_skipping_aug;
|
}
|
}
|
else
|
else
|
d->state = state_error;
|
d->state = state_error;
|
if (d->state == state_skipping_aug && d->aug_size == 0)
|
if (d->state == state_skipping_aug && d->aug_size == 0)
|
d->state = state_wait_loc4;
|
d->state = state_wait_loc4;
|
break;
|
break;
|
|
|
case state_skipping_aug:
|
case state_skipping_aug:
|
if ((int)*pnbytes < 0)
|
if ((int)*pnbytes < 0)
|
d->state = state_error;
|
d->state = state_error;
|
else
|
else
|
{
|
{
|
int left = (d->aug_size -= *pnbytes);
|
int left = (d->aug_size -= *pnbytes);
|
if (left == 0)
|
if (left == 0)
|
d->state = state_wait_loc4;
|
d->state = state_wait_loc4;
|
else if (left < 0)
|
else if (left < 0)
|
d->state = state_error;
|
d->state = state_error;
|
}
|
}
|
break;
|
break;
|
|
|
case state_wait_loc4:
|
case state_wait_loc4:
|
if (*pnbytes == 1
|
if (*pnbytes == 1
|
&& exp->X_op == O_constant
|
&& exp->X_op == O_constant
|
&& exp->X_add_number == DW_CFA_advance_loc4)
|
&& exp->X_add_number == DW_CFA_advance_loc4)
|
{
|
{
|
/* This might be a DW_CFA_advance_loc4. Record the frag and the
|
/* This might be a DW_CFA_advance_loc4. Record the frag and the
|
position within the frag, so that we can change it later. */
|
position within the frag, so that we can change it later. */
|
frag_grow (1);
|
frag_grow (1);
|
d->state = state_saw_loc4;
|
d->state = state_saw_loc4;
|
d->loc4_frag = frag_now;
|
d->loc4_frag = frag_now;
|
d->loc4_fix = frag_now_fix ();
|
d->loc4_fix = frag_now_fix ();
|
}
|
}
|
break;
|
break;
|
|
|
case state_saw_loc4:
|
case state_saw_loc4:
|
d->state = state_wait_loc4;
|
d->state = state_wait_loc4;
|
if (*pnbytes != 4)
|
if (*pnbytes != 4)
|
break;
|
break;
|
if (exp->X_op == O_constant)
|
if (exp->X_op == O_constant)
|
{
|
{
|
/* This is a case which we can optimize. The two symbols being
|
/* This is a case which we can optimize. The two symbols being
|
subtracted were in the same frag and the expression was
|
subtracted were in the same frag and the expression was
|
reduced to a constant. We can do the optimization entirely
|
reduced to a constant. We can do the optimization entirely
|
in this function. */
|
in this function. */
|
if (d->cie_info.code_alignment > 0
|
if (d->cie_info.code_alignment > 0
|
&& exp->X_add_number % d->cie_info.code_alignment == 0
|
&& exp->X_add_number % d->cie_info.code_alignment == 0
|
&& exp->X_add_number / d->cie_info.code_alignment < 0x40)
|
&& exp->X_add_number / d->cie_info.code_alignment < 0x40)
|
{
|
{
|
d->loc4_frag->fr_literal[d->loc4_fix]
|
d->loc4_frag->fr_literal[d->loc4_fix]
|
= DW_CFA_advance_loc
|
= DW_CFA_advance_loc
|
| (exp->X_add_number / d->cie_info.code_alignment);
|
| (exp->X_add_number / d->cie_info.code_alignment);
|
/* No more bytes needed. */
|
/* No more bytes needed. */
|
return 1;
|
return 1;
|
}
|
}
|
else if (exp->X_add_number < 0x100)
|
else if (exp->X_add_number < 0x100)
|
{
|
{
|
d->loc4_frag->fr_literal[d->loc4_fix] = DW_CFA_advance_loc1;
|
d->loc4_frag->fr_literal[d->loc4_fix] = DW_CFA_advance_loc1;
|
*pnbytes = 1;
|
*pnbytes = 1;
|
}
|
}
|
else if (exp->X_add_number < 0x10000)
|
else if (exp->X_add_number < 0x10000)
|
{
|
{
|
d->loc4_frag->fr_literal[d->loc4_fix] = DW_CFA_advance_loc2;
|
d->loc4_frag->fr_literal[d->loc4_fix] = DW_CFA_advance_loc2;
|
*pnbytes = 2;
|
*pnbytes = 2;
|
}
|
}
|
}
|
}
|
else if (exp->X_op == O_subtract)
|
else if (exp->X_op == O_subtract)
|
{
|
{
|
/* This is a case we can optimize. The expression was not
|
/* This is a case we can optimize. The expression was not
|
reduced, so we can not finish the optimization until the end
|
reduced, so we can not finish the optimization until the end
|
of the assembly. We set up a variant frag which we handle
|
of the assembly. We set up a variant frag which we handle
|
later. */
|
later. */
|
int fr_subtype;
|
int fr_subtype;
|
|
|
if (d->cie_info.code_alignment > 0)
|
if (d->cie_info.code_alignment > 0)
|
fr_subtype = d->cie_info.code_alignment << 3;
|
fr_subtype = d->cie_info.code_alignment << 3;
|
else
|
else
|
fr_subtype = 0;
|
fr_subtype = 0;
|
|
|
frag_var (rs_cfa, 4, 0, fr_subtype, make_expr_symbol (exp),
|
frag_var (rs_cfa, 4, 0, fr_subtype, make_expr_symbol (exp),
|
d->loc4_fix, (char *) d->loc4_frag);
|
d->loc4_fix, (char *) d->loc4_frag);
|
return 1;
|
return 1;
|
}
|
}
|
break;
|
break;
|
|
|
case state_error:
|
case state_error:
|
/* Just skipping everything. */
|
/* Just skipping everything. */
|
break;
|
break;
|
}
|
}
|
|
|
return 0;
|
return 0;
|
}
|
}
|
|
|
/* The function estimates the size of a rs_cfa variant frag based on
|
/* The function estimates the size of a rs_cfa variant frag based on
|
the current values of the symbols. It is called before the
|
the current values of the symbols. It is called before the
|
relaxation loop. We set fr_subtype{0:2} to the expected length. */
|
relaxation loop. We set fr_subtype{0:2} to the expected length. */
|
|
|
int
|
int
|
eh_frame_estimate_size_before_relax (fragS *frag)
|
eh_frame_estimate_size_before_relax (fragS *frag)
|
{
|
{
|
offsetT diff;
|
offsetT diff;
|
int ca = frag->fr_subtype >> 3;
|
int ca = frag->fr_subtype >> 3;
|
int ret;
|
int ret;
|
|
|
diff = resolve_symbol_value (frag->fr_symbol);
|
diff = resolve_symbol_value (frag->fr_symbol);
|
|
|
if (ca > 0 && diff % ca == 0 && diff / ca < 0x40)
|
if (ca > 0 && diff % ca == 0 && diff / ca < 0x40)
|
ret = 0;
|
ret = 0;
|
else if (diff < 0x100)
|
else if (diff < 0x100)
|
ret = 1;
|
ret = 1;
|
else if (diff < 0x10000)
|
else if (diff < 0x10000)
|
ret = 2;
|
ret = 2;
|
else
|
else
|
ret = 4;
|
ret = 4;
|
|
|
frag->fr_subtype = (frag->fr_subtype & ~7) | ret;
|
frag->fr_subtype = (frag->fr_subtype & ~7) | ret;
|
|
|
return ret;
|
return ret;
|
}
|
}
|
|
|
/* This function relaxes a rs_cfa variant frag based on the current
|
/* This function relaxes a rs_cfa variant frag based on the current
|
values of the symbols. fr_subtype{0:2} is the current length of
|
values of the symbols. fr_subtype{0:2} is the current length of
|
the frag. This returns the change in frag length. */
|
the frag. This returns the change in frag length. */
|
|
|
int
|
int
|
eh_frame_relax_frag (fragS *frag)
|
eh_frame_relax_frag (fragS *frag)
|
{
|
{
|
int oldsize, newsize;
|
int oldsize, newsize;
|
|
|
oldsize = frag->fr_subtype & 7;
|
oldsize = frag->fr_subtype & 7;
|
newsize = eh_frame_estimate_size_before_relax (frag);
|
newsize = eh_frame_estimate_size_before_relax (frag);
|
return newsize - oldsize;
|
return newsize - oldsize;
|
}
|
}
|
|
|
/* This function converts a rs_cfa variant frag into a normal fill
|
/* This function converts a rs_cfa variant frag into a normal fill
|
frag. This is called after all relaxation has been done.
|
frag. This is called after all relaxation has been done.
|
fr_subtype{0:2} will be the desired length of the frag. */
|
fr_subtype{0:2} will be the desired length of the frag. */
|
|
|
void
|
void
|
eh_frame_convert_frag (fragS *frag)
|
eh_frame_convert_frag (fragS *frag)
|
{
|
{
|
offsetT diff;
|
offsetT diff;
|
fragS *loc4_frag;
|
fragS *loc4_frag;
|
int loc4_fix;
|
int loc4_fix;
|
|
|
loc4_frag = (fragS *) frag->fr_opcode;
|
loc4_frag = (fragS *) frag->fr_opcode;
|
loc4_fix = (int) frag->fr_offset;
|
loc4_fix = (int) frag->fr_offset;
|
|
|
diff = resolve_symbol_value (frag->fr_symbol);
|
diff = resolve_symbol_value (frag->fr_symbol);
|
|
|
switch (frag->fr_subtype & 7)
|
switch (frag->fr_subtype & 7)
|
{
|
{
|
case 0:
|
case 0:
|
{
|
{
|
int ca = frag->fr_subtype >> 3;
|
int ca = frag->fr_subtype >> 3;
|
assert (ca > 0 && diff % ca == 0 && diff / ca < 0x40);
|
assert (ca > 0 && diff % ca == 0 && diff / ca < 0x40);
|
loc4_frag->fr_literal[loc4_fix] = DW_CFA_advance_loc | (diff / ca);
|
loc4_frag->fr_literal[loc4_fix] = DW_CFA_advance_loc | (diff / ca);
|
}
|
}
|
break;
|
break;
|
|
|
case 1:
|
case 1:
|
assert (diff < 0x100);
|
assert (diff < 0x100);
|
loc4_frag->fr_literal[loc4_fix] = DW_CFA_advance_loc1;
|
loc4_frag->fr_literal[loc4_fix] = DW_CFA_advance_loc1;
|
frag->fr_literal[frag->fr_fix] = diff;
|
frag->fr_literal[frag->fr_fix] = diff;
|
break;
|
break;
|
|
|
case 2:
|
case 2:
|
assert (diff < 0x10000);
|
assert (diff < 0x10000);
|
loc4_frag->fr_literal[loc4_fix] = DW_CFA_advance_loc2;
|
loc4_frag->fr_literal[loc4_fix] = DW_CFA_advance_loc2;
|
md_number_to_chars (frag->fr_literal + frag->fr_fix, diff, 2);
|
md_number_to_chars (frag->fr_literal + frag->fr_fix, diff, 2);
|
break;
|
break;
|
|
|
default:
|
default:
|
md_number_to_chars (frag->fr_literal + frag->fr_fix, diff, 4);
|
md_number_to_chars (frag->fr_literal + frag->fr_fix, diff, 4);
|
break;
|
break;
|
}
|
}
|
|
|
frag->fr_fix += frag->fr_subtype & 7;
|
frag->fr_fix += frag->fr_subtype & 7;
|
frag->fr_type = rs_fill;
|
frag->fr_type = rs_fill;
|
frag->fr_subtype = 0;
|
frag->fr_subtype = 0;
|
frag->fr_offset = 0;
|
frag->fr_offset = 0;
|
}
|
}
|
|
|
